Differential clinical profile of candesartan compared to other angiotensin receptor blockers

Pharmacokinetics and bioequivalence study of candesartan cilexetil tablet in Chinese volunteers under fasting condition: an open-label, randomized-sequence, 2-period crossover study

Candesartan is an antihypertensive agent that acts on an angiotensin II receptor. Candesartan cilexetil is a prodrug that is converted into the active form of candesartan during intestinal absorption. This study aimed to assess the pharmacokinetics and bioequivalence of a reference and a test formulation of candesartan cilexetil tablets in healthy Chinese volunteers. A randomized, open-label, single-dose, crossover study was conducted with two treatment periods. Forty-eight healthy Chinese volunteers participated under fasted conditions. Qualified subjects were randomly divided into two groups (1:1 ratio) to receive either the test or reference formulation first. A washout period of 14 days separated the administration of the two formulations. Blood samples were collected at specific time points and analyzed for candesartan concentration using Ultra High-Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS). The maximum concentration (Cmax), the AUC from time zero to the last measured time point (AUC0-t) and the AUC from time zero to infinity (AUC0-∞) fell within the bioequivalence range of 80% to 125%. These results suggest that the test and reference formulations of candesartan cilexetil tablets are bioequivalent, meaning they have similar rates and extents of absorption in healthy Chinese volunteers. No serious adverse events or side effects were reported throughout the study.

Novel Insights in the Hypertension Treatment & Type 2 Diabetics Induced by Angiotensin Receptor Blockers: MD Simulation Studies & Molecular Docking of Some Promising Natural Therapies

Angiotensin receptor blockers (ARBs) are commonly used to treat hypertension that target the hormonal system (renin-angiotensin system (RAS)), which regulates various physiological functions in the body. ARBs work by blocking the binding of angiotensin II to its receptor, thereby preventing a rise in blood pressure. These drugs not only normalize the overactivation of RAS but also provide protective effects against cardiovascular, renal, and type 2 diabetic patients. Inappropriate RAS activity has been linked to insulin resistance of type 2 diabetes. Olmesartan, as an ARB, was found to have a beneficial role in reducing postprandial glucose levels in type 2 diabetes. However, ARBs can cause side effects, prompting a search for new compounds that have fewer adverse effects. This study explores the potential of natural metabolites, specifically eugenol, gallic acid, myricetin, p-cymene, quercetin, and kaempferol, as ARB inhibitors compared to the current standard, olmesartan. Using in silico studies, the binding affinity of these natural substances to the ARB receptor was evaluated. The results showed that myricetin and kaempferol had affinities higher than those of olmesartan, suggesting that they could serve as promising ARB inhibitors for hypertension treatment. These natural compounds could provide an alternative approach to conventional antihypertensive drugs, which may have fewer side effects. However, more research is needed to validate the efficacy and safety of these natural compounds as antihypertensive drugs. Further in vitro and in vivo studies are needed to confirm their effectiveness and safety. This study provides a promising starting point for future investigations into the potential of natural metabolites as alternative treatments for hypertension. The findings also highlight the importance of exploring natural alternative treatments for hypertension and the protective effects of ARBs on early stage type-2 diabetics.

Different responses of the MIO‑M1 Mueller cell line to angiotensin II under hyperglycemic or hypoxic conditions

Members of the renin-angiotensin aldosterone system (RAAS) are expressed by various retinal tissues including Mueller glial cells. As the RAAS is hypothesized to play an important role in the pathogenesis of diseases that threaten vision, such as diabetic macular edema or retinal vein occlusion, the possible changes induced by exposure of the human cell line MIO-M1, an established model of Mueller cells, to angiotensin II or aldosterone for 6 h under hypoxic and/or hyperglycemic conditions were investigated. The mRNA expression levels of the members of the RAAS were assessed by reverse transcription-quantitative PCR, and the secretion of cytokines was assessed by ELISA. Under hyperglycemic conditions, the mRNA expression levels of the angiotensin-converting enzyme 2 (ACE2), angiotensin II receptors, AT1 and AT2, and the receptor of angiotensin (1-7) MAS1 were significantly higher after exposure to angiotensin II, and the expression of ACE2, AT2, and IL-6 (a marker of inflammation) was significantly increased after treatment with aldosterone; the expression of the other targets investigated remained unchanged. Significantly more IL-6 was secreted by MIO-M1 cells exposed to hyperglycemia and angiotensin. When cells were cultured in a hypoxic environment, additional treatment with aldosterone significantly increased the mRNA expression levels of ACE, but significantly more ACE2 mRNA was expressed in the presence of angiotensin II. Under hypoxic plus hyperglycemic conditions, significantly less ACE but more AT2 was expressed after treatment with angiotensin II, which also led to strongly elevated expression of IL-6. The mRNA expression levels of the angiogenic growth factor VEGF-A and secretion of the encoded protein were notably increased under hypoxic and hypoxic plus hyperglycemic conditions, irrespective of additional treatment with angiotensin II or aldosterone. These findings suggest that angiotensin II induces a pro-inflammatory response in MIO-M1 cells under hyperglycemic conditions despite activation of the counteracting ACE2/MAS1 signaling cascade. However, hypoxia results in an increased expression of angiogenic VEGF-A by these cells, which is not altered by angiotensin II or aldosterone.

Determination of candesartan or olmesartan in hypertensive patient plasma using UPLC-MS/MS

Candesartan and olmesartan are angiotensin II receptor blockers (ARBs) used for the treatment of hypertension and heart failure. Quantitation methods for candesartan and olmesartan were developed using ultra-high performance liquid chromatography-tandem mass spectrometry following protein precipitation. Candesartan was separated using 5 mM ammonium formate (A) and 100% acetonitrile (B) and olmesartan was separated using 2 mM ammonium formate with 0.1% formic acid (A) and 100% acetonitrile (B). Separation was performed using an isocratic method with a Thermo hypersil GOLD C18 column. Electrospray ionization was used for analyte ionization and detection of candesartan, olmesartan, and the internal standards by multiple reaction monitoring. Developed method showed excellent linearity (r > 0.99) in the concentration range of 2-500 ng/mL for candesartan and 5-2,500 ng/mL for olmesartan. Accuracies were 86.70-108.8% for candesartan and 87.87-112.6% for olmesartan. These methods were able to successfully measure plasma candesartan or olmesartan concentrations in hypertensive patients. This study can be used for pharmacokinetic studies of candesartan or olmesartan in humans.

Real world effectiveness and tolerability of candesartan in the treatment of migraine: a retrospective cohort study

To date, two randomized, controlled studies support the use of candesartan for migraine prophylaxis but with limited external validity. We aim to evaluate the effectiveness and tolerability of candesartan in clinical practice and to explore predictors of patient response. Retrospective cohort study including all patients with migraine who received candesartan between April 2008-February 2019. The primary endpoint was the number of monthly headache days during weeks 8-12 of treatment compared to baseline. Additionally, we evaluated the frequency during weeks 20-24. We analysed the percentage of patients with 50% and 75% response rates and the retention rates after three and 6 months of treatment. 120/4121 patients were eligible, aged 45.9 [11.5]; 100 (83.3%) female. Eighty-four patients (70%) had chronic migraine and 53 (42.7%) had medication-overuse headache. The median number of prior prophylactics was 3 (Inter-quartile range 2-5). At baseline, patients had 20.5 ± 8.5 headache days per month, decreasing 4.3 ± 8.4 days by 3 months (weeks 12-16) and by 4.7 ± 8.7 days by 6 months (paired Student's t-test, p < 0.001). The percentage of patients with a 50% response was 32.5% at 3 months and 31.7% at 6 months, while the retention rate was 85.0% and 58.3%. The number of prior treatments (Odds ratio 0.79, 95% CI 0.64-0.97) and the presence of daily headache (Odds ratio 0.39, 95% CI 0.16-0.97) were associated with a lower probability of response. Candesartan showed beneficial effects in the preventive treatment of migraine in clinical practice, including patients with chronic migraine, medication-overuse headache and resistance to prior prophylactics.

Electroacupuncture Improved Chronic Cerebral Hypoperfusion-Induced Anxiety-Like Behavior and Memory Impairments in Spontaneously Hypertensive Rats by Downregulating the ACE/Ang II/AT1R Axis and Upregulating the ACE2/Ang-(1-7)/MasR Axis

Electroacupuncture (EA) can effectively alleviate anxiety disorders and memory impairments caused by various neurodegenerative diseases; however, the molecular mechanisms underlying its neuroprotective effects are unclear. Previous studies have shown that the renin-angiotensin system (RAS) comprises of two axes with mutual antagonism: the classical angiotensin converting enzyme/angiotensin II/angiotensin II type 1 receptor (ACE/Ang II/AT1R) axis and the protective angiotensin converting enzyme 2/angiotensin-(1-7)/Mas receptor (ACE2/Ang-(1-7)/MasR) axis. In this study, we observed that chronic cerebral hypoperfusion (CCH) mediated anxiety-like behavior and memory impairments in spontaneously hypertensive rats (SHR) via upregulation of the hippocampal classical axis (ACE/Ang II/AT1R) and the partial hippocampal protective axis (ACE2/Ang-(1-7)). However, Ang II levels were much higher than those of Ang-(1–7), indicating that the ACE/Ang II/AT1R axis plays a dominant role in the comorbidity of CCH and hypertension. Moreover, candesartan cilexetil (Canc) and perindopril (Peril) were used as positive control drugs. We found that EA, Canc, and Peril attenuated CCH-induced anxiety-like behavior and memory impairments in SHR, potentially via downregulation of the hippocampal classical axis (ACE/Ang II/AT1R) and upregulation of the whole hippocampal protective axis (ACE2/Ang-(1-7)/MasR). These results suggest that EA therapy for CCH with hypertension may be mediated by two hippocampal RAS axes.

The place of ARBs in heart failure therapy: is aldosterone suppression the key?

Since the launch of the first orally available angiotensin II (AngII) type 1 receptor (AT₁R) blocker (ARB) losartan (Cozaar) in the late 1990s, the class of ARBs (or ‘sartans’, short for Angiotensin-RecepTor-ANtagonistS) quickly expanded to include candesartan, eprosartan, irbesartan, valsartan, telmisartan, and olmesartan. All ARBs have high affinity for the AT₁ receptor, expressed in various tissues, including smooth muscle cells, heart, kidney, and brain. Since activation of AT₁R, the target of these drugs, leads, among other effects, to vascular smooth muscle cell growth, proliferation and contraction, activation of fibroblasts, cardiac hypertrophy, aldosterone secretion from the adrenal cortex, thirst-fluid intake (hypervolemia), etc., the ARBs are nowadays one of the most useful cardiovascular drug classes used in clinical practice. However, significant differences in their pharmacological and clinical properties exist that may favor use of particular agents over others within the class, and, in fact, two of these drugs, candesartan and valsartan, continuously appear to distinguish themselves from the rest of the ‘pack’ in recent clinical trials. The reason(s) for the potential superiority of these two agents within the ARB class are currently unclear but under intense investigation. The present short review gives an overview of the clinical properties of the ARBs currently approved by the United States Food and Drug Administration, with a particular focus on candesartan and valsartan and the areas where these two drugs seem to have a therapeutic edge. In the second part of our review, we outline recent data from our laboratory (mainly) on the molecular effects of the ARB drugs on aldosterone production and on circulating aldosterone levels, which may underlie (at least in part) the apparent clinical superiority of candesartan (and valsartan) over most other ARBs currently in clinical use.

The renin-angiotensin system: a possible new target for depression

Depression remains a debilitating condition with an uncertain aetiology. Recently, attention has been given to the renin-angiotensin system. In the central nervous system, angiotensin II may be important in multiple pathways related to neurodevelopment and regulation of the stress response. Studies of drugs targeting the renin-angiotensin system have yielded promising results. Here, we review the potential beneficial effects of angiotensin blockers in depression and their mechanisms of action. Drugs blocking the angiotensin system have efficacy in several animal models of depression. While no randomised clinical trials were found, case reports and observational studies showed that angiotensin-converting enzyme inhibitors or angiotensin receptor blockers had positive effects on depression, whereas other antihypertensive agents did not. Drugs targeting the renin-angiotensin system act on inflammatory pathways implicated in depression. Both preclinical and clinical data suggest that these drugs possess antidepressant properties. In light of these results, angiotensin system-blocking agents offer new horizons in mood disorder treatment.

Neurorestoration after traumatic brain injury through angiotensin II receptor blockage

See Moon (doi:10.1093/awv239) for a scientific commentary on this article.Traumatic brain injury frequently leads to long-term cognitive problems and physical disability yet remains without effective therapeutics. Traumatic brain injury results in neuronal injury and death, acute and prolonged inflammation and decreased blood flow. Drugs that block angiotensin II type 1 receptors (AT1R, encoded by AGTR1) (ARBs or sartans) are strongly neuroprotective, neurorestorative and anti-inflammatory. To test whether these drugs may be effective in treating traumatic brain injury, we selected two sartans, candesartan and telmisartan, of proven therapeutic efficacy in animal models of brain inflammation, neurodegenerative disorders and stroke. Using a validated mouse model of controlled cortical impact injury, we determined effective doses for candesartan and telmisartan, their therapeutic window, mechanisms of action and effect on cognition and motor performance. Both candesartan and telmisartan ameliorated controlled cortical impact-induced injury with a therapeutic window up to 6 h at doses that did not affect blood pressure. Both drugs decreased lesion volume, neuronal injury and apoptosis, astrogliosis, microglial activation, pro-inflammatory signalling, and protected cerebral blood flow, when determined 1 to 3 days post-injury. Controlled cortical impact-induced cognitive impairment was ameliorated 30 days after injury only by candesartan. The neurorestorative effects of candesartan and telmisartan were reduced by concomitant administration of the peroxisome proliferator-activated receptor gamma (PPARγ, encoded by PPARG) antagonist T0070907, showing the importance of PPARγ activation for the neurorestorative effect of these sartans. AT1R knockout mice were less vulnerable to controlled cortical impact-induced injury suggesting that the sartan's blockade of the AT1R also contributes to their efficacy. This study strongly suggests that sartans with dual AT1R blocking and PPARγ activating properties have therapeutic potential for traumatic brain injury.

The renin-angiotensin system and prevention of age-related functional decline: where are we now?

Declining physical function is a major health problem for older adults as it is associated with multiple comorbidities and mortality. Exercise has been shown to improve physical function, though response to exercise is variable. Conversely, drugs targeting the renin-angiotensin system (RAS) pathway, including angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs), are also reported to improve physical function. In the past decade, significant strides have been made to understand the complexity and specificity of the RAS system as it pertains to physical function in older adults. Prior findings have also determined that interactions between antihypertensive medications and exercise may influence physical function above and beyond either factor alone. We review the latest research on RAS, exercise, and physical function for older adults. We also outline future research aims in this area, including genetic influences and clinical phenotyping, for the purpose of maintaining or improving physical function through tailored treatments.

Candesartan cilexetil 32 mg/hydrochlorothiazide 25 mg in unselected patients with high or very high cardiovascular risk: efficacy, safety, and metabolic impact

BACKGROUND AND OBJECTIVES

Safety and efficacy of the fixed-dose combination candesartan cilexetil 32 mg/hydrochlorothiazide 25 mg has been demonstrated in a number of randomized clinical trials. Because stringent inclusion and exclusion criteria prohibit many high-risk patients from being investigated in clinical trials we aimed to assess the effectiveness, tolerability, and safety in a large unselected cohort of high-risk patients in primary care. The primary objective was the efficacy of candesartan cilexetil 32 mg/hydrochlorothiazide 25 mg in lowering the office-based blood pressure (BP). Secondary objectives were changes of metabolic parameters and safety.

METHODS

A multicenter, non-interventional study of patients with a BP ≥ 140 mmHg systolic and/or 90 mmHg diastolic and additional cardiovascular risk factors. Patients received the fixed-dose combination of candesartan cilexetil 32 mg and hydrochlorothiazide 25 mg for 24 weeks.

RESULTS

A total of 3,390 patients with a mean age of 61.7 ± 10.6 years, 57.8 % being male, and a mean body mass index of 29.7 kg/m(2) were documented. Of these, 70.9 % had at least one additional cardiovascular risk factor such as coronary artery disease (45.5 %) or diabetes mellitus (44.5 %). Baseline BP was 159.6 ± 15.3 over 93.5 ± 9.5 mmHg. BP at 24 weeks was reduced by 32.3 ± 15.8 systolic and 16.1 ± 10.2 mmHg diastolic compared with baseline (p < 0.001 each). Systolic BP (SBP) and diastolic BP (DBP) was normalized (<140/<90 mmHg) in 57.4 % of non-diabetic patients. An SBP <140 mmHg or SBP reduction of ≥ 20 mmHg was achieved by 77.9 % non-diabetic patients. Fasting plasma glucose (-5.9 mg/dL), glycosylated hemoglobin (-0.18 %), low-density lipoprotein cholesterol (-8.5 mg/dL) and triglycerides (-20.3 mg/dL) were reduced significantly, high-density lipoprotein was increased by 0.18 %, while potassium and creatinine levels remained stable. The proportion of patients with adverse drug reactions (ADRs) was 1.3 % (n = 61 events in 45 patients). There were ten serious ADRs in eight patients; four patients died without causal relationship to study drug.

CONCLUSIONS

The results confirm previous randomized clinical trial data supporting the effectiveness, tolerability, and safety of this fixed-dose combination in an unselected patient population with high cardiovascular risk.